For example, pressure sensors for detecting the pressure prevailing in a shared fuel accumulator (so-called common rail) of a fuel injection system of a motor vehicle are known from the related art. The fuel stored under the measured pressure in the accumulator is provided for injection into combustion chambers of an internal combustion engine of the motor vehicle. Such pressure sensors are connected to an electronic control and/or regulating unit (so-called engine control unit, ECU). The pressure sensors communicate via analog communication channels with the ECU. These analog channels may be manipulated relatively easily, whereby it is possible for unauthorized persons to achieve a performance enhancement of the internal combustion engine (so-called tuning). This performance enhancement is advantageous for the driver of a motor vehicle provided with the performance-enhanced internal combustion engine and generally desired thereby.
However, such tuning is not recognizable and not comprehensible for the vehicle manufacturer. This has the disadvantage that the vehicle manufacturer in the past was made liable for any problems which resulted from the impermissible performance enhancement and had to repair defects of the internal combustion engine, although these were sometimes to be attributed to the impermissible performance enhancement. For some time, many of the analog communication channels between sensors and the ECU have been replaced by digital data buses. A variety of possibilities is known from the related art for recognizing a manipulation of the sensor data digitally transmitted from the sensor to the ECU and/or of the sensor itself or to secure the sensor data and/or the sensor against a manipulation.
A corresponding method for recognizing a manipulation of transmitted sensor data and/or a sensor itself is discussed, for example, in DE 10 2009 002 396 A1. Many of the methods may have the disadvantage that they are relatively costly and complex. They place relatively high demands on the software and the hardware which are necessary to implement the manipulation recognition according to the known methods. Thus, for example, it is necessary in the case of the method known from the cited publication that two keys for generating and verifying authentication codes (so-called message authentication codes, MACs) for the data transmitted between the sensor and the ECU must be stored both in the sensor and in the ECU. This requires additional storage space both in the sensor and in the ECU, storage space being scarce and costly in the sensor in particular. In addition, the computer program for implementing the manipulation protection is relatively complex, and computing-intensive and storage-intensive as a result of the complexity of the method. In addition, substantial computing power is necessary to be able to process the complex computer program within acceptable processing times in the sensor or in the ECU.